US 2104589 A
Description (OCR text may contain errors)
Jan. 4, 1938. F. w. HARTMAN REFRIGERATING APPARATUS Filed Feb. 25, 1934 4 Sheets-Sheet 1 INVENTOR Jan. 4, 1938. F. w. HARTMAN REFR IGERATING APPARATUS Filed Feb. 23, 1934 4 Sheets-Sheet '2 a zilvzn'rola ;ATTORNE Patented Jan. 4,1938
PATENT OFFICE Y REFRIGERATINGAPPARATUS Frank W. Hartman, Detroit, Mich. Application February 23, 1934, SerialNo. 112,633
This invention relates to refrigerated apparatus and more particularly to refrigerated apparatus for administering oxygen to patients requiring oxygen treatment.
Modern oxygen therapy, which involves the use of high concentrations of oxygen under closely controlled conditions, may be said to date from the investigations of Haldane in England and of Meltzer in the UnitedStates during 1917. These M investigations servedto direct attention to the effectiveness of high concentrations of oxygen in the treatment of pneumonia and other'diseases. During the past few years the fundamental factors underlying oxygen therapy have been scientifically studied by a number of investigators and methods have been developed for the practical application of the data thus obtained.
Thalheimer, in his work, The Modern Hospital, has said that the oxygen atmosphere fore the control of these two factors has been most diificult with the types of oxygen therapy apparatus available and it is not uncommon to find in some of the heretofore .known types of apparatus that the temperature rises to 85 or 90 F. and the relative humidity to 70% or 80%. A good combination, on the other handis about 70 F. with 40% relative humidity.
' With the objections of heretofore known apparatus in mind and in order to maintain the proper temperature and humidity within the tent, I employ thermostatically controlled electric refrigeration for cooling and dehumidifying the .tent air, where the cooling preferably, although 7, not necessarily, takes place directly within the tent.
As a further object of my invention, with a view to overcoming mechanical objections to prior existing tents, I have evolved a new canopy allowing full visibility for both patients and attendants, the new canopy being also readily portable and movable so as to allow easy access to the patient by the attendant.
Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.
In the drawings:
; tus in section, together with a bed provided with] should be kept cool and relatively dry. I-iereto- Fig. 1 is a perspective view' of a portabletype (oi. 12a-191) duct means connected to the refrigerating apparatus;
Fig. 3 is a perspective-view showing a somewhat less portable, but more compact type of oxygen administering apparatus embodying another form of my invention;
Fig. 4 is another perspective view of a portion of the apparatus shown in Fig.3;
Fig. 5 is a perspective view .of a head portion of a hospital bed together with another form of my oxygen administering apparatus;
Fig. 6 is a horizontal sectional view through the duct means shown in Fig. 5; and
Fig. 7 is a vertical sectional view taken along the line 7-1 of Fig. 6.
Referring to the drawings and more particularly to' Fig. 1, there is shown a portable oxygen administering unit provided with large swivel castors 2i having in its lower portion a compartment 22 containing a refrigerant liquefying apparatus including a compressor, a condenser, and a-Freceiver. This refrigerating apparatus preferably has a large condenser surface so that only a relatively slowly moving air stream is required for cooling of the condenser. The compressor is also of the slow speed type so as to reduce the noise. Above the chamber 22 is provided an insulated chamber 23 containing a plurality of evaporating coils 25 formed of finned tubing. These evaporating, coils 26 are 'provided within the ducts 25-and 26. A slow speed centrifugal fan 21 is provided for drawing air through the duct means 25 and 26 over the surfaces of the evaporating coils 24. This centrifugal fan 21 is driven by a variable speed electric motor 28 under the control of a suitable rheostat or other suitable controlling means 29. The fan 2'! draws air from the head portion of the enclosure near the top thereof through a square-shaped aluminum duct 30 which is in the formof an arc and [connects to a horizontal duct 3| resting upon the mattress which in turn is connected by a flexible duct 32 to the ducts 25 and 26 in the portable unit 20. The air which is drawn from the enclosure through the duct 30 is returned. by the fan 21 through a flexible duct 33 and a square rigid horizontal duct 34 which connects to a cross duct 35 at the foot of the bed. This cross duct 35 is provided with a plurality of outi lets/so as to discharge a di-Eused supply of cooled and oxygenated air at the foot end of the enclosure.
At one end of the portable unit 20 there is pro I vided a supporting means for the canopy in the I form of a verticalptubular member i0 within which there is provided a counterweight attached to a chain 4| which extends over a pulley 42 at the top of the tubular member 40. Parallel with the tubular member 40 is a guide and supporting rod 43 upon which slidingly mounted is a T- shaped bracket 44 which may be locked thereto by a. suitable locking device 45. This bracket 44 is connected to'the opposite end of the chain 4| so that it, together with the canopy, is balanced by the counterweight within the tubular member 40. Connected to one leg of the T-shaped bracket 44 is a swivel bracket 46 which is provided with a suitable lock nut". The angular position of this swivel bracket is controlled by a hand wheel 48. This swivel bracket 46 is connected to an elongated U-shaped member 49 which is pivotally connected at both ends tqthe semi-cylindrical shaped canopy 50.
This canopy 50 is provided with a rectangular frame 5| to which the bracket 49 is pivoted. Fastened to this frame 5| at the opposite end of the canopy is a semi-circular shaped piece and over this semi-circular shaped piece there extend from one side of the rectangular frame 5| to the other, a plurality of spaced sheets of a suitable translucent sheet material such as Cellophane or some suitable cellulose nitrate or acetate product 52 provided with one or more dead air spaces therebetween for insulating purposes. Extending downwardly from the lower edge of this semioylindrical canopy is a skirt 53 of some suitable A material, such as a rubberized fabric or sponge end a stop cook 56 and oxygen flow meter 51' which control the supply of oxygen through a small tube 59, under the control of a secondstop cook 58, to the flexible duct 33 within which it is carried by the circulating air into the interior of the canopy.
The portable unit 20 is adapted to be connected to a source of electric energy -by means of the electric cord, and is provided with a suitable electric switch SI for controlling its operation.
The operation of the refrigerating apparatus is also controlled by a suitable mercury tube type of thermostat 62 which is connected to the refrigerating apparatus by a suitable electric cord 63. This thermostat is provided with a sealed mercury tube type of switch means because of the presence of oxygen within the canopy. By means of this thermostat 52 and the rheostat 29, the temperature and humidity of the air or atmosphere within the'tent is controlled automatically. I
In Figs. 3 and 4 an oxygen administering device more suitable for large hospitals is disclosed. In this form, thecanopy I0 is provided with a tubular duct means 1| at its lower edge which also forms the rectangular frame for the canopy. This canopy is provided with a semi-circular member .one side of the duct means .over the arcuate periphery of the semi-circular member to the '11 for the duct means ll.
other side of the duct means ll so as to form a rigid half-cylinder. Extending downwardly from the canopy there is provided a suitable skirt 15 of rubberized fabric or sponge rubber, the lower end of which skirt may be tucked in under the mattress or other parts of the bed clothing.
At the head end'of the canopy III is an air inlet This air inlet 11 connects with the rectangular duct means H,
' through a small duct 19, shown in Fig. 4. This with electric energy through the electric cord 82 under the control of a suitable rheostat 83. This air passes over the refrigerant evaporating coils between the duct means causing the temperature of this air to be reduced and also causing some dehydration of this air. The moisture which is removed from the air collects in the duct means and is drawn off from time to time through a I suitable drain llll. After passing through the rectangular duct means the air is discharged from a plurality of apertures at the opposite end of the enclosure. 7|
In order to conserve space, the refrigerant liquefying apparatus is housed within a cabinet provided with small castors so as to make it portable. This cabinet 85 is made low and fiat sothat it can be readily placed'under any hospital bed. The refrigerant supply'and return conduits 85 extend from this unit and are fastened to the vertical tubular supporting means 81. This vertical tubular supporting means is mounted upon the'portable truck unit 88 which may be fastened to the cabinet 85. The refrigerant supply conduit is provided with a suitable adjustable expansion valve 88 so as to control the flow of liquid refrigerant to the expansion coils 18 within the duct means. By adjusting the expansion valve the evaporating temperature within the expansion coil may be controlled and this varies the cooling effect and the amount of dehydration. The refrigerant from the expansion valve 89 is supplied to the expansion coils I8 by-a flexible refrigerant conduit 90 and the evaporated refrigerant is returned through a flexible conduit 9|. The refrig erating apparatus'is automatically controlled by a sealed mercury tube type of thermostat 82 which is mounted within the canopy. The canopy is pivotally connected to an enlarged U-shaped bracket 93 which in turn is connected to a swivel bracket 94 which is adjustably mounted upon the tubular supporting member 81. i
In order to supply oxygen to the interior of the enclosure. there is provided an oxygen cylinder 95 provided-with a suitable stop took 96 and an oxygen flow meter 91 in order to control the supply of oxygen through the flexible tube 98 to the duct means II. The duct means ll carries this oxygen into the interior of the enclosure.
In Figs. 5, 6 and 7 another form of. oxygen administering apparatus is disclosed. form, there is provided a rectangular light weight tubular framework llll provided with an upwardly-extending arched tubular member III at one end and a pair of spaced semi-circular wall members H2 and H3 at' the'opposite end also supported by the rectangular tubular frame NO.
In this The arched rod or tubular member Ill and the 75 port an arched translucent sheet H4 of some I suitable adhesive.
suitable material such as Cellophane or-a cellulose nitrate or acetate product. This translucent sheet H4 forms the top of the canopy or tent,
generally designated by the reference character H5. At the end of the tent H5 adjacent the arched tubular member III there is provided a translucent sheet H6 of similar material as the sheet H4. The sheets l I4 and I I6 are fastened to the tubular framework and the semi-circular wall members by any uitable means, such as a Extending downwardly. from the rectangular tubular framework H are the flexible curtains III which provide an air seal between the 'tent or canopy I I and the bed I I8. These flexible curtains are preferably made of rubber-or rubberized fabric so as to permit the escape of carbon dioxide from the tent but to retain the oxygen and the air therein.
Connected to the double walled portion formed of the-semi-circular wall members H2 and H3 is a duct means H9 which,'as better shown in Figs. 6 and 7, extends through the wall member H3 and is fastened to the" wall member H2.
, Rubber gaskets I20 and I2I cooperating with the flanges I65 and I66 are provided for sealing the duct means H9 tothe wall members I I2 and I I3. The duct means H9 is provided with a vertical finned type of evaporating means I22 formed of horizontally serpentine refrigerant ducts provided with vertical fins. Moisture condenses upon these vertical fins and runs down the fins and is collected in a shallow pan I23 beneath the evaporating unit I22. The. shallow pan I23 collects the condensed moisture and discharges it through a drain cock I24 into a larger pan I26 which is supported by'a bracket I21 beneath the evaporating means I22.
At one side of 'the evaporating means I22 there is provided a filter I28 formed of a screen enclosure I29 which contains some suitable filter and absorbent material I30, such as activated or granulated charcoal and soda lime, the latter being calcium oxide and sodium hydroxide. This filter removes carbon dioxide from the air by ad sorption and also removes moisture and impurities from the'air. At the end of the duct means H9 there is provided a quiet slow speed centrifugal fan I3I which draws air from the interior I32 of the tent or canopy H5 through the screen I33 at the entrance of the duct means H9 and through the evaporating means I22 and the filter I30. This slow speed centrifugal fan is connected'through an opening provided with an air seal I34 to a small electric motor I35 located outside of the duct means H9. The centrifugal fan I3I discharges the air into a duct I36 which connects to the space I31 between the inner semi-circular wall member H2 and the outer semi-circular wall member H3. The wall member H2 is provided with apertures I38 at widely distributed points to provide'diffused supply of cooled filtered air to the interior of the tent or canopy H5.
The duct'means I I9 and the tent or canopy' I I5 are supported by the brackets I40 and MI which are fastened together as well as fastened to the duct means H9 and the outer wall H3.
bracketv I40 continues downwardly and is adjustably fastened within a kerf I42 by a clamping screw I43 in the top of a vertically slidable rod I44 which is received within a tubular pedestal I45 and adjustably held by a clamping set screw I46. This tubular pedestal I45 is supported at The.
means I22 and is returned to the refrigerant liquefying apparatus through an insulated return conduit I52. By adjusting the expansion valve I50, the evaporating pressure and temperature within the evaporating means I22 may be controlled and this evaporating temperature varies the cooling effect upon the circulating air and controls the amount of dehydration.
The operation of the refrigerating system is controlled by a thermostat I53 mounted upon the wall member H2 and connected by an electrical conductor I54 to a connection or junction box I55 which is mounted upon the cabinet I38. This connection or junction box I55 is connected to the refrigerant liquefying apparatus by an electrical conductor I64 and to the electric fan motor I through the electrical conductor I56 and finger switch I51 which controls the operation of the fan motor and centrifugal fan. The connection box I55 is also connected by indexible electric conductor I58 to a suitable source of supply forsupplying the electric energy to the refrigerant liquefying apparatus and the electric fan motor 835.
The truck unit cylinder I59 which is provided with the usual stop cock I60 at its upper end which stop cock controls the flow of oxygen to an oxygen flow motor I6I which in turn controls the rate of flow of oxygen through the flexible tube I62 to the duct I36, where it diffuses into the air discharged by the centrifugal fan I3I and is conducted to the space I3! between the wall members H2 and H3 from. which the mixture of oxygen and air is conducted I46 also supports an oxygen v through the distributed apertures I38 into the interior of the tent above the patient. This oxygenated air slowly falls within'the tent to the level of the patient while the warm air' rises and is withdrawn through the duct means H9. With this apparatus I am able to maintain a temperature of 68 F. and a relative humidity of even during the hottest and most humid summer weather. I also obtain an oxygen concentration of from 55% to 58% with an average of from 6 to 8 liters of oxygen supplied per minut'e.. In my refrigerating system -.I use as a re- I frigerant gas a fluorochloro derivative of an aliphatic hydrocarbon, such as dichlorodifluoromethane whichis non-toxic, non-odorous, and non-explosive. By the thermostat and humidity control, these conditions are maintained automatically without constant attention by the attendants.
With my improved type of canopy a very light enclosure with almost complete visibility is provided. By means of the pivoted mounting of the canopy, the canopy may readily be rotated so that the patient can read ly enter and leave the enclosure and this alsc facilitates caring for the patient. The swivel mounting of the canopy enables the head portion of the bed to be raised and one end of the canopy to be raised' along tending upwardly from one side thereof, a tent means for circulating the atmosphere within the tent over the closed evaporating member, a refrigerant liquefying apparatus separate from the tent, flexible tubular connections connecting the refrigerant liquefying apparatus with the closed evaporating member for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the closed evaporating member to cool thecirculating atmosphere within the tent, and means for supplying oxygen to the tent.
2. Oxygen administering apparatus including a supporting member adapted to rest upon the floor, said supporting member having means exstructure supported by said upwardly extending means but located to one-side thereof over said supporting member, a closed refrigerant evaporating member supported by said tent structure in heat exchange relation with the atmosphere within the tent, said supporting member having a refrigerant liquefyingapparatus thereon, low in height and adapted to be moved under a bed with the tent directly over the bed and the upwardly extending means at one side of the bed, said ree frigera-nt liquefying apparatus being connected to the closed evaporating member to supply liquid refrigerant and for withdrawing evaporated refrigerant from the closed evaporating member, and means forsupplying oxygen within the tent.
3. Oxygen administering apparatus including a rigid frame structure, a closed refrigerant evaporating means supported by the frame structure and a covering means stretched over the frame structure forming a tent, said closed evaporating means being in heat exchange relation with the atmosphere within the tent, a' refrigerant liquefying apparatus exposed to the atmosphere without the tent but connected in closed circuit relationship with the evaporating means to supply liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, and means for supplying oxygen to the tent.
4. Oxygen administering apparatus including a tent enclosing at least the head of the patient, a closed evaporating means in heat exchange relation with the atmosphere in the tent, a refrigerant liquefying means inclosed circuit relation with said'closed evaporating means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, means for regulating the evaporating temperature of the evaporating means and thermostatic being adjustable to permit movement of the tent structure, a rigid duct means supported by said framework and in communication with and movable with said tent structure, a refrigerant evapcrating means within said duct means, fan means for drawing air from the tent, circulating the air through said duct means in heat exchange relation with the evaporating means and returning the circulated air to the tent, a refrigerant liquefying means supported by said supporting structure independently of the tent structure, and flexible refrigerant conduit means connecting the liquefying means and the evaporating means.
6. Oxygen administering apparatus including a movable tent structure having a relatively rigid supporting framework, a supporting st'ruc ture having an adjustable connection with said framework for supporting the tent structure over a. bed to enclose the head of a patient in the bed, a refrigerant evaporating means fixed to the framework of said tent structure and in heat exchange relation with the atmosphere within the tent, a refrigerant liquefying means supported by said supporting structure independently of the tent structure, and flexible refrigerant conduit means connecting the liquefying means and the evaporating means.
7. Oxygen administering apparatus including a movable tent structure having a relatively rigid supporting framework, a supporting structure having an adjustable connection with said framework for supporting the tent structure over a bed to enclose the head of a patient in the bed, a refrigerant evaporating means fixed to the framework of said tent structure and in heat exchange relation with the atmosphere within the tent, a refrigerant liquefying means supported by said supporting structure independently of the tent structure, and flexible refrigerant conduit means connecting the liquefying means and the evaporating means, an oxygen supply means mounted upon said supporting structure, and flexible conduit means extending from the oxygen supply means into communication with the atmosphere in-the tent.
8. Oxygen administering apparatus including a framework, a translucent sheet means supported by the framework and forming the top of a tent, said tent having side walls extending downwardly into contact with a bed for enclosing at least the head of a patient, a supporting means connected to said framework for supporting the tent over the bed, a refrigerant. evaporating means supported by said framework in heat exchange relation with the atmosphere within the tent, means for supplying oxygen tothe atmosphere of the tent, and a refrigerant liquefying means connected to said evaporating means.
9. Oxygen administering apparatus including a supporting member adapted to rest upon the floor, said' supporting member having means extending upwardly from one side thereof, a tent structure supported by said upwardly extending means but located to one'side thereof over said supporting member, a closed refrigerant evaporating member in heat exchange relation with 'the atmosphere within the tent, said supporting member having a refrigerant liquefying apparatus thereon, said supporting member being adaptedto be moved under-the bed with the tent directly over the bed and the upwardly extending means at one side of the bed, said-refrigerant liquefying apparatus being connected to the closed evaporating member to supply liquid refrigerant and for withdrawing evaporated refrigerant from the closed evaporating member,
and means for supplying oxygen to the atmosphere within the tent.
10. A portable self-contained oxygenadministering'and atmosphere cooling apparatus including a truck; a laterally extending tent carried by the truck; a refrigerating system carried entirely v on the truck and including an evaporator, a compressor for withdrawing gaseous refrigerant from the evaporator and for compressing the same, an electric motor for driving the compressor, an air cooled condenser 'operatively connected with the compressor and evaporator; means carried on the truck and forming a duct system including the adapted to be positioned underneath the-bed; a
standard carried by the truck adjacent one end thereof and adapted to be positioned alongside the bed; a tent adapted to extend over the bed and carried by the standard; a retrigerating system carried entirely on the truck and adapted to be positioned underneath the bed, said refrigerating system including an evaporator, a com-.
pressor or withdrawing gaseous refrigerant from the evaporator and for compressing the same, an electric motor for driving the compressor, an air cooled condenser operatively connected with the compressor and evaporator; means carried on the truck and forming a duct system; including the interior of the tent and the space about the evaporator; an oxygen tank carried by the truck and having its outlet connected into the duct system; and control means for the apparatus.
FRANK HARTMAN. 20